Conventionally, a seamless capsule of the above-mentioned type is manufactured by a so-called air nozzle method, as disclosed in, e.g., Japanese Patent Laid-Open No. HEI4-338230, which uses a concentric multiple nozzle comprising a center nozzle and an annular nozzle which concentrically surrounds the center nozzle. That is, a liquid filler material is discharged from the center nozzle of the concentric multiple nozzle, and at the same time a liquid capsule shell material is discharged from the annular nozzle surrounding the center nozzle, thereby forming a composite flow having a concentric columnar form in which the capsule shell material flows so as to cover the outside of the filler material flow. A vibration is applied to the composite flow to cut the composite flow from its lower end in the air, thereby forming a droplet. This droplet is dropped onto the liquid surface of a curing liquid and brought into contact with the curing liquid to cure the capsule shell material. In this way, a spherical seamless capsule is manufactured by encapsulating the filler material with the capsule shell material.
The air nozzle method has the problem that the droplets cut in the air deform when they drop onto and collide against the liquid surface of the curing liquid, and this produces irregularity in the sphericity of manufactured seamless capsules.
It is, therefore, a main object of the present invention to provide a seamless capsule manufacturing method for obtaining high-quality seamless capsules without irregularity.